Display device

ABSTRACT

A display device includes a panel, a backlight, and an adhesive tape. The backlight is placed under the panel. The adhesive tape has a light blocking property and is bonded to an end face of the panel and the backlight.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of application Ser. No. 15/616,246,filed Jun. 7, 2017, which claims the benefit of priority of the priorJapanese Patent Application No. 2016-134206, filed on Jul. 6, 2016, theentire contents of which are incorporated herein by reference.

FIELD

The embodiments discussed herein are related to a display device.

BACKGROUND

In recent years transmission type display devices have widely been usedin smartphones, personal assistant devices (PADs), tablet computers, carnavigation systems, and the like. A transmission type display deviceincludes a liquid crystal panel and a backlight disposed (placed) on arear surface side of the liquid crystal panel and irradiating the liquidcrystal panel with light and displays an image by the use of the lightwith which the backlight irradiates the liquid crystal panel. With sucha display device a technique for preventing light with which a backlightirradiates a liquid crystal panel from leaking out is proposed.Furthermore, with a display device a technique for fixing a backlightand a liquid crystal panel is proposed.

See, for example, U.S. Patent Application Publication No. 2015/0241731.

SUMMARY

According to an aspect, there is provided a display device including apanel, a backlight under the panel, and an adhesive tape having a lightblocking property and bonded to an end face of the panel and thebacklight.

The object and advantages of the invention will be realized and attainedby means of the elements and combinations particularly pointed out inthe claims.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and arenot restrictive of the invention.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a plan view of a display device according to a firstembodiment;

FIG. 2 is an exploded perspective view of the display device accordingto the first embodiment;

FIG. 3 is an exploded perspective view of a liquid crystal panel in thefirst embodiment;

FIG. 4 is an exploded perspective view of a backlight in the firstembodiment;

FIGS. 5A and 5B are fragmentary sectional views of the display deviceaccording to the first embodiment;

FIGS. 6A and 6B are fragmentary sectional views of modification 1 of thedisplay device according to the first embodiment;

FIG. 7 is a fragmentary sectional view of modification 2 of the displaydevice according to the first embodiment;

FIG. 8 is a fragmentary sectional view of a display device according toa second embodiment;

FIG. 9 is a fragmentary sectional view of a display device according toa third embodiment;

FIGS. 10A and 10B are fragmentary sectional views of a display deviceaccording to a fourth embodiment; and

FIG. 11 is a fragmentary sectional view of a display device according toa fifth embodiment.

DESCRIPTION OF EMBODIMENTS

Embodiments will now be described with reference to the accompanyingdrawings.

Disclosed embodiments are simple examples. It is a matter of course thata proper change which suits the spirit of the invention and which willreadily occur to those skilled in the art falls within the scope of thepresent invention. Furthermore, in order to make description clearer,the width, thickness, shape, or the like of each component mayschematically be illustrated in the drawings compared with the realstate. However, it is a simple example and the interpretation of thepresent invention is not restricted.

In addition, in the present invention and the drawings the samecomponents that have already been described in previous drawings aremarked with the same numerals and detailed descriptions of them may beomitted according to circumstances.

First Embodiment

First a display device according to a first embodiment will be describedby the use of FIGS. 1 and 2. FIG. 1 is a plan view of a display deviceaccording to a first embodiment. FIG. 1 is a plan view of a displaydevice viewed from the side of a front surface (surface on which animage is displayed). FIG. 2 is an exploded perspective view of thedisplay device according to the first embodiment. In the followingdescription of each component, it is assumed that a surface on a side(upper side in FIG. 2) of the display device on which an image isdisplayed is a front surface and that a surface on the opposite side(lower side in FIG. 2) of the front surface is a rear surface.

As illustrated in FIG. 2, a display device 10 is a transmission typedisplay device and includes a cover 100, a bonding member 110, a liquidcrystal panel (panel, hereinafter) 120, an adhesive tape 130, abacklight 140, and an adhesive tape 150.

The cover 100 has a rectangular shape whose four corners are rounded andcovers a display screen 120 a, which is a front surface of the panel120, to protect the display screen 120 a. Furthermore, the size of thecover 100 formed is such that the peripheral edge (outer edge) of thecover 100 protrudes out from the peripheral edge of the panel 120 inplanar view.

The cover 100 is formed by the use of a glass plate or a transparentresin. The cover 100 includes a transmission section 101 and aframe-shaped light blocking section 102 by which the perimeter of thetransmission section 101 is enclosed. The transmission section 101 is anarea which transmits light, and is opposed to a display area 120 b ofthe panel 120. The light blocking section 102 is a light blocking areaformed by locating a light blocking member which shields light on therear surface side of the glass plate. The light blocking section 102 isalso referred to as a frame area of the display device 10. The lightblocking member may be disposed on the front surface side of the glassplate.

The bonding member 110 bonds the cover 100 and the display screen 120 aof the panel 120 together. The bonding member 110 has great transparencyand an adhesive property (adhesion) and is ultraviolet curing resin orthe like. The bonding member 110 is formed so as to have a rectangularshape in planar view.

The panel 120 is a display unit in the shape of a flat plate whichdisplays an image. The panel 120 includes the display area 120 b onwhich an image is displayed, and a frame-shaped frame area 120 c bywhich the perimeter of the display area 120 b is enclosed. The panel 120has the transmission display function of displaying (forming) an imageon the display screen 120 a by selectively transmitting light emittedfrom the backlight 140 to the display area 120 b.

The panel 120 will now be described more concretely by the use of FIG.3. FIG. 3 is an exploded perspective view of the liquid crystal panel inthe first embodiment.

The panel 120 corresponds to a lateral electric field mode as a displaymode in which a lateral electric field approximately parallel to theprincipal plane of a substrate is mainly utilized. The panel 120 maycorrespond to a longitudinal electric field mode in which a longitudinalelectric field approximately perpendicular to the principal plane of thesubstrate is mainly utilized.

The panel 120 includes an upper substrate 121, a lower substrate 122, apolarizer 123, a polarizer 124, and drive control flexible printedcircuits (FPC) 125.

The upper substrate 121 and the lower substrate 122 are paired andliquid crystal is put between them. The upper substrate 121 is a flatplate having a rectangular shape. For example, red (R), green (G), andblue (B) color filters corresponding to pixels are formed on the uppersubstrate 121. The lower substrate 122 is a flat plate having arectangular shape. A thin-film transistor and the like are formed on thelower substrate 122.

The polarizer 123 is stuck to the upper substrate 121 in a state inwhich the polarizer 123 is disposed on the front surface side of theupper substrate 121. The polarizer 123 polarizes light that is thenoutput from the panel 120. The polarizer 124 is stuck to the lowersubstrate 122 in a state in which the polarizer 124 is disposed on therear surface side of the lower substrate 122. The polarizer 124polarizes light entering the panel 120.

The drive control FPC 125 is a circuit board on which an integratedcircuit, such as an IC chip, and the like are mounted and which suppliesa signal needed for driving the panel 120. The drive control FPC 125 isstuck to the lower substrate 122 and extends from one side of the lowersubstrate 122 in planar view. On the basis of a signal supplied from thedrive control FPC 125, the panel 120 selectively transmits light emittedfrom the backlight 140 to the display area 120 b to display an image onthe display screen 120 a. The description will return to FIGS. 1 and 2.

The adhesive tape 130 is placed between the panel 120 and the backlight140. The adhesive tape 130 is a double-sided tape which bonds the panel120 and the backlight 140 together to fix them. The adhesive tape 130has a light blocking property by, for example, making a base materialblack, and has the shape of a frame. This means that a portion of theadhesive tape 130 corresponding to the display area 120 b is open. Thatis to say, the adhesive tape 130 bonds (fixes) the panel 120 and thebacklight 140 together in planar view in an area placed under the framearea 120 c.

The backlight 140 is placed on the rear surface side of the panel 120and outputs light to the rear surface of the panel 120 corresponding tothe display area 120 b.

The adhesive tape 150 is a tape having a light blocking property. Theadhesive tape 150 is bonded to an end face of the panel 120 to bond(fix) the backlight 140 and the panel 120 together.

The backlight 140 and the adhesive tape 150 will now be describedconcretely by the use of FIG. 4. FIG. 4 is an exploded perspective viewof the backlight in the first embodiment.

As illustrated in FIG. 4, the backlight 140 includes a light guide 141,light sources 142 a to 142 h, a light source control FPC 143, opticalsheets 144 to 146, a frame 147, and a reflector 148.

The light sources 142 a to 142 h are placed on the FPC 143 in a state inwhich the light sources 142 a to 142 h are aligned. Each of the lightsources 142 a to 142 h emits light toward an end face (hereinafterreferred to as the light entrance surface) of the light guide 141. Thelight sources 142 a to 142 h are light emitting diodes (LEDs).

The light source control FPC 143 is a circuit board which suppliessignals needed for the light sources 142 a to 142 h placed along thelight entrance surface of the light guide 141. Part of the FPC 143extends in planar view in a direction in which the distance from thelight guide 141 increases. The extending portion extends outside theframe 147 in a state in which the backlight 140 is assembled. On thebasis of signals supplied from the FPC 143, the backlight 140 controlsthe light sources 142 a to 142 h to adjust light entering the lightguide 141. As a result, the rear surface of the panel 120 is irradiatedwith light of desired intensity.

The light guide 141 has a rectangular shape in planar view. The lightsources 142 a to 142 h are opposed to the light entrance surface of thelight guide 141. The light guide 141 diffuses light from each lightsource entering the light guide 141 from the light entrance surface andoutputs light from a front surface (hereinafter referred to as the lightoutput surface). Furthermore, the light from the light output surfaceenters the panel 120 from the rear surface via the optical sheets 144 to146. The light entrance surface is placed on the side on which the drivecontrol FPC 125 of the panel 120 is placed.

The optical sheets 144 to 146 are transparent optical members placed onthe light output surface side of the light guide 141 and adjust theoptical characteristics of light output from the light guide 141. Forexample, the optical sheet 144 is a diffuser and the optical sheets 145and 146 are prism sheets.

The frame 147 has the shape of a rectangular frame and is placed so asto enclose the perimeters of the light guide 141, the light sources 142a to 142 h, the FPC 143, and the optical sheets 144 to 146. The frame147 is bonded to the reflector 148 with the adhesive tape 150 placedbetween the frame 147 and the reflector 148.

The frame 147 has a stepped shape (also referred to as an L shape). Thatis to say, its lower portion protrudes out from its upper portion to aninner periphery side in a cross-sectional view. Furthermore, in a statein which the backlight 140 is assembled, the lower portion of the frame147 is opposed to the end face of the light guide 141 and the upperportion of the frame 147 is opposed to end faces of the optical sheets144 to 146. The optical sheets 144 to 146 extend to a position where theoptical sheets 144 to 146 are situated over the lower portion of theframe 147 in planar view.

The adhesive tape 150 is a double-sided tape having the shape of arectangular frame. The adhesive tape 150 includes a pair of a short side154 along the FPC 143 and a short side 152 parallel to the short side154 and a pair of long sides 151 and 153 which connect end portions ofthe pair of short sides 152 and 154. Furthermore, the width of the pairof long sides 151 and 153 is greater than that of the pair of shortsides 152 and 154. Before the display device 10 is assembled, the pairof long sides 151 and 153 extend outside the backlight 140 asillustrated in FIG. 2.

The reflector 148 is placed on the rear surface side of the light guide141 and is placed over the entire surface of the frame 147 and theentire surface of the light guide 141 in planar view. The reflector 148returns light from the light guide 141 to the light guide 141. Thereflector 148 has the functions of reflection, diffusion, scattering,and the like. As a result, light entering the light guide 141 from eachof the light sources 142 a to 142 h is efficiently utilized.Furthermore, the reflector 148 contributes to an increase in theintensity of light emitted from the backlight 140.

The reflector 148 is, for example, foamed polyethylene terephthalate(PET). A silver-evaporated film, a multilayer reflection film, whitePET, or the like may be used as the reflector 148.

As has been described, with the backlight 140 the reflector 148 isbonded to the frame 147 with the adhesive tape 150 therebetween. A casewhose upper portion is open is formed by the reflector 148 and the frame147. Furthermore, the light guide 141, the light sources 142 a to 142 h,the light source control FPC 143, and the optical sheets 144 to 146 arehoused in the case formed of the reflector 148 and the frame 147.

The structure of a section of the display device will now be described.FIGS. 5A and 5B are fragmentary sectional views of the display deviceaccording to the first embodiment. FIG. 5A is a sectional view taken inthe direction of the arrow A-A of FIG. 1. FIG. 5B is a sectional viewtaken in the direction of the arrow B-B of FIG. 1. In order to simplifyfigures, partial sections are illustrated, excluding the cover 100 andthe bonding member 110.

A section of a left side portion (see FIG. 1) of the display device 10has the same bonding structure that a section of the A-A portion (rightside portion in FIG. 1) of the display device 10 has. Furthermore, asection of a lower side portion (see FIG. 1) of the display device 10may have the same bonding structure that a section of the B-B portion(upper side portion in FIG. 1) of the display device 10 has.

As illustrated in FIGS. 5A and 5B, with the display device 10 an endface of the backlight 140 protrudes out from an end face of the panel120. As a result, there is a level difference between the end face ofthe panel 120 and the end face of the backlight 140.

As illustrated in FIG. 5A, the long side 151 of the adhesive tape 150placed in the right side portion of the display device 10 includes afirst bonding area 151 a and a second bonding area 151 b. The firstbonding area 151 a and the second bonding area 151 b are integrallyformed. Furthermore, with the display device 10 the first bonding area151 a and the second bonding area 151 b are placed in regular positionsby bending the long side 151 at the border between the first bondingarea 151 a and the second bonding area 151 b. Positions where the firstbonding area 151 a and the second bonding area 151 b are placed will nowbe described concretely.

The first bonding area 151 a is placed between the frame 147 and thereflector 148 to bond (fix) the frame 147 and the reflector 148together.

An end portion of the first bonding area 151 a on the opposite side ofthe second bonding area 151 b is placed in a position where the frame147 is situated in planar view over the end portion of the first bondingarea 151 a on the opposite side of the second bonding area 151 b.Furthermore, the width of the first bonding area 151 a formed is set soas to meet needed bonding strength (fixing strength).

The second bonding area 151 b includes a bonding portion 151 b 1 on thepanel side bonded to the end face of the panel 120, a bonding portion151 b 2 on the light guide side bonded to the end face of the lightguide 141, and a connection portion 151 b 3 which connects the bondingportion 151 b 1 and the bonding portion 151 b 2. Furthermore, theconnection portion 151 b 3 is placed so as to fall from the bondingportion 151 b 1 to the bonding portion 151 b 2. As a result, the secondbonding area 151 b covers the level difference between the end face ofthe panel 120 and the end face of the backlight 140. Furthermore, theconnection portion 151 b 3 of the second bonding area 151 b is opposedto the frame 147 of the backlight 140 and the polarizer 124 with adetermined clearance (space) therebetween. In view of these respects, itis desirable to eliminate adhesive force from an inner face of theconnection portion 151 b 3 opposed to the frame 147 and the like.However, there may be cases where adhesive force is not eliminated fromthe inner face of the connection portion 151 b 3.

In addition, the second bonding area 151 b extends from end faces of theupper substrate 121 and the lower substrate 122 (hereinafter referred toas the pair of substrates 121 and 122). A portion of the second bondingarea 151 b extending from the end faces of the pair of substrates 121and 122 is bent along the pair of substrates 121 and 122. Furthermore,an end face of the portion of the second bonding area 151 b bent alongthe pair of substrates 121 and 122 is opposed to an end face of thepolarizer 123. In this state, the portion of the second bonding area 151b bent along the pair of substrates 121 and 122 is bonded to aperipheral edge portion (portion not covered with the polarizer 123) ofa front surface of the upper substrate 121.

The portion of the second bonding area 151 b bent along the pair ofsubstrates 121 and 122 is equal to or smaller than the polarizer 123 inthickness.

As illustrated in FIG. 5B, on the other hand, the short side 152 of theadhesive tape 150 placed in the upper side portion of the display device10 includes a first bonding area 152 a.

The first bonding area 152 a is placed between the frame 147 and thereflector 148 to bond (fix) the frame 147 and the reflector 148together.

The first bonding area 152 a is placed in a position where the frame 147is placed in planar view over the whole of the first bonding area 152 a.Furthermore, the width of the first bonding area 152 a formed is set soas to meet needed bonding strength (fixing strength).

As has been described, with the display device 10 the adhesive tape 150having a light blocking property is bonded to the end face of the panel120. This prevents light from leaking out from the end face of the panel120.

Furthermore, the adhesive tape 150 is bonded not only to the end face ofthe panel 120 but also to the front surface of the upper substrate 121.This increases a bonding area. In addition, the adhesive tape 150 isbonded to the panel 120 not only in the vertical direction but also inthe horizontal direction of FIGS. 5A and 5B. As a result, the adhesivetape 150 is difficult to peel from the panel 120.

Moreover, with the display device 10 the panel 120 and the backlight 140are bonded together (fixed) not only with the adhesive tape 130 but alsowith the adhesive tape 150. Accordingly, the panel 120 and the backlight140 are bonded together (fixed) more firmly. As a result, a positionaldeviation does not occur between the panel 120 and the backlight 140,that is to say, there is no clearance between the panel 120 and thebacklight 140. This prevents light from leaking out.

Furthermore, an outer peripheral face of the frame 147 and the end faceof the panel 120 are covered with the adhesive tape 150. Accordingly,the end face of the panel 120 is protected and impact resistance isimproved.

In addition, the outer peripheral face of the frame 147 and the end faceof the panel 120 are covered with the adhesive tape 150. This preventsdust, moisture, or the like from entering, and improves reliability.

As illustrated in FIGS. 5A and 5B, with the display device 10 theoptical sheets 144 to 146 are opposed to the adhesive tape 130, but theoptical sheets 144 to 146 are not bonded to the adhesive tape 130. Thatis to say, there is clearance (space) between the optical sheets 144 to146 and the adhesive tape 130. The optical sheets 144 to 146 are bondedto the panel 120, the light guide 141, and the like in the lower sideportion (on the light source side) of the display device 10, but theoptical sheets 144 to 146 are not bonded to the panel 120, the lightguide 141, or the like in the three remaining side portions (right side,left side, and upper side portions) of the display device 10. As aresult, the optical sheets 144 to 146 accommodate thermal expansion orcontraction and the occurrence of a display degradation phenomenon, suchas moire, is prevented. Furthermore, because the optical sheets 144 to146 are opposed to the adhesive tape 130, end portions of the opticalsheets 144 to 146 look better.

The description has been given on the assumption that each of the leftside portion and the right side portion adjacent to the lower sideportion of the display device 10 illustrated in FIG. 1 in which thelight source control FPC 143 is placed has the structure illustrated inFIG. 5A. However, the upper side portion of the display device 10illustrated in FIG. 1 may also have the same structure as that of thesection of the A-A portion.

(Modification 1)

Modification 1 will now be described by the use of FIGS. 6A and 6B.FIGS. 6A and 6B are fragmentary sectional views of modification 1 of thedisplay device according to the first embodiment. Partial sectionsillustrated in FIGS. 6A and 6B correspond to the partial sectionsillustrated in FIGS. 5A and 5B respectively.

As illustrated in FIGS. 6A and 6B, with a display device 10 a which ismodification 1 of the display device 10 according to the firstembodiment, the adhesive tape 130 used in the display device 10 isremoved. Furthermore, there is no space between a polarizer 124 and anoptical sheet 146. A backlight 140 and a panel 120 are fixed in a statein which the polarizer 124 is placed on the optical sheet 146.

Modification 1 of the display device 10 has been described. By removingthe adhesive tape 130 in this way, the display device 10 a is madethinner than the display device 10. In addition, the display device 10 ahaving a narrow frame is realized.

With the display device 10 illustrated in FIGS. 5A and 5B, usually adisplay area is set by setting a determined clearance inside an areasituated over the adhesive tape 130 in planar view. With the displaydevice 10 a illustrated in FIGS. 6A and 6B, on the other hand, theadhesive tape 130 is removed. Therefore, unlike the display device 10,there is no need to meet the following restriction. A display area isset inside an area situated over the adhesive tape 130.

As a result, with the display device 10 a the distance from a peripheraledge of a display screen 120 a of the panel 120 to a display area 120 bis short compared with the display device 10. Therefore, the displaydevice 10 a having a narrow frame is realized.

With the display device 10 a the backlight 140 and the panel 120 arebonded together (fixed) with an adhesive tape 150. Accordingly, even ifthe adhesive tape 130 is removed, bonding strength (fixing strength) isensured.

Of course it is understood that other functions and effects which areobtained by the situation described in the first embodiment and whichare clear from the specification or which are conceivable by thoseskilled in the art according to circumstances are realized by thepresent disclosure.

(Modification 2)

Modification 2 will now be described by the use of FIG. 7. FIG. 7 is afragmentary sectional view of modification 2 of the display deviceaccording to the first embodiment. A partial section illustrated in FIG.7 corresponds to the partial section illustrated in FIG. 5A.

As illustrated in FIG. 7, with a display device 10 b which ismodification 2 of the display device 10 according to the firstembodiment, a long side 151 of an adhesive tape 150 includes a secondbonding area 151 b. A portion of the second bonding area 151 b extendingfrom end faces of a pair of substrates 121 and 122 is not bent along thepair of substrates 121 and 122 but extends. The display device 10 b mayhave a structure in which an end face of the second bonding area 151 bis leveled with a front surface of the upper substrate 121 or astructure in which an end face of the second bonding area 151 b isbonded to the end face of the upper substrate 121 in a position nearerto the lower substrate 122 than to the front surface of the uppersubstrate 121.

Modification 2 of the display device 10 has been described. Of course itis understood that other functions and effects which are obtained by thesituation described in the first embodiment and which are clear from thespecification or which are conceivable by those skilled in the artaccording to circumstances are realized by the present disclosure.

Second Embodiment

A second embodiment differs from the first embodiment in the dispositionof an adhesive tape (position where an adhesive tape is placed).Description will now be given with importance attached especially to thedifferences between the first embodiment and a second embodiment. Asecond embodiment will be described concretely by the use of FIG. 8.FIG. 8 is a fragmentary sectional view of a display device according toa second embodiment. FIG. 8 illustrates a partial section of a displaydevice according to a second embodiment corresponding to the partialsection illustrated in FIG. 5A.

In order to simplify a figure, a partial section is illustrated,excluding a cover 100 and a bonding member 110. A section of a left sideportion of a display device according to a second embodiment has thesame bonding structure that a section of a right side portion of adisplay device according to a second embodiment has.

With a display device 10 c according to a second embodiment a frame 247whose section has a simple shape, that is to say, whose inner peripheryis flattened is used in place of the frame 147 which is used in thedisplay device 10 according to the first embodiment and whose sectionhas a complex shape. Furthermore, the frame 247 is placed in a state inwhich its inner periphery is opposed to an end face of a light guide 141and end faces of optical sheets 144 to 146.

In addition, an adhesive tape 250 is used in place of the adhesive tape150 used in the display device 10 according to the first embodiment. Theadhesive tape 250 is a single-sided tape having adhesive force only onone face.

As illustrated in FIG. 8, a long side 251 of the adhesive tape 250placed in the right side portion of the display device 10 c includes afirst bonding area 251 a and a second bonding area 251 b. The firstbonding area 251 a and the second bonding area 251 b are integrallyformed. Furthermore, with the display device 10 c the first bonding area251 a and the second bonding area 251 b are placed in regular positionsby bending the long side 251 at the border between the first bondingarea 251 a and the second bonding area 251 b. Positions where the firstbonding area 251 a and the second bonding area 251 b are placed will nowbe described concretely.

The first bonding area 251 a is bonded to a rear surface of thereflector 148.

The second bonding area 251 b is bonded to the end face of the panel 120and an outer peripheral face of the frame 247.

Furthermore, the second bonding area 251 b extends from end faces of apair of substrates 121 and 122. A portion of the second bonding area 251b extending from the end faces of the pair of substrates 121 and 122 isbent along the pair of substrates 121 and 122. In addition, an end faceof the portion of the second bonding area 251 b bent along the pair ofsubstrates 121 and 122 is opposed to an end face of the polarizer 123.In this state, the portion of the second bonding area 251 b bent alongthe pair of substrates 121 and 122 is bonded to a peripheral edgeportion (portion not covered with a polarizer 123) of a front surface ofthe upper substrate 121.

The portion of the second bonding area 251 b bent along the pair ofsubstrates 121 and 122 is equal to or smaller than the polarizer 123 inthickness.

As has been described, with the display device 10 c the adhesive tape250 is bonded to the rear surface of the reflector 148 and the outerperipheral face of the frame 247. As a result, restrictions on the shapeof the frame 247 are reduced. Usually the width of a frame formed is setso as to ensure a bonding area which meet desired bonding strength. Inthe first embodiment, for example, the frame 147 is bonded to the panel120 on the upper end side and is bonded to the reflector 148 on thelower end side. Accordingly, there is a need to form the frame 147 so asto make the area of an upper end face of the frame 147 larger than orequal to an area which meets bonding strength between the frame 147 andthe panel 120 and so as to make the area of an lower end face of theframe 147 larger than or equal to an area which meets bonding strengthbetween the frame 147 and the reflector 148.

In addition, with a display device usually a display area is set bysetting a determined clearance inside an area situated over a frame inplanar view. Accordingly, as illustrated in FIGS. 5A and 5B, forexample, in order to realize a narrow width (narrow frame) whileensuring a bonding area on each of the upper end face and the lower endface of the frame 147, the frame 147 is formed so as to have a steppedshape. That is to say, its lower portion protrudes out from its upperportion to an inner periphery side in a cross-sectional view.

With the display device 10 c, on the other hand, the adhesive tape 250is bonded to the rear surface of the reflector 148 and the outerperipheral face of the frame 247. As a result, the frame 247 is formedso as to make the area of an upper end face of the frame 247 an areawhich meets bonding strength between the frame 247 and the panel 120.Accordingly, the frame 247 may be formed so as to have, for example, arectangular shape (inner periphery is flattened) in a cross-sectionalview as illustrated in FIG. 8.

As has been described, there are no restrictions on the area of a lowerend face of the frame 247. As a result, with the display device 10 c thewidth of the frame 247 may be made smaller than that of the frame 147.Accordingly, a display device having a narrow frame is realized.

In addition, the first bonding area 251 a of the long side 251 of theadhesive tape 250 is bonded to the rear surface of the reflector 148. Asa result, even if the first bonding area 251 a is situated on the innerperiphery side of the frame 247 (in an area under a display area, forexample) in planar view, the first bonding area 251 a does not exertinfluence on display. Accordingly, with the display device 10 c abonding area between the first bonding area 251 a and the reflector 148may be made large. This makes it difficult to peel the adhesive tape 250from the reflector 148.

With the display device 10 c a backlight 140 a and the panel 120 arebonded together (fixed) with the adhesive tape 250. Therefore, as withmodification 1 in the first embodiment, the display device 10 c having anarrow frame is realized by removing an adhesive tape 130. An upper sideportion of the display device according to the second embodiment mayalso have the same structure as the right side portion illustrated inFIG. 8 has.

The second embodiment has been described. The same functions and effectsare also obtained for matters in the second embodiment which are thesame as those in the above first embodiment.

Furthermore, of course it is understood that other functions and effectswhich are obtained by the situation described in the second embodimentand which are clear from the specification or which are conceivable bythose skilled in the art according to circumstances are realized by thepresent disclosure.

Third Embodiment

A third embodiment differs from the first embodiment in the dispositionof an adhesive tape (position where an adhesive tape is placed) and theabsence of a frame. Description will now be given with importanceattached especially to the differences between the first embodiment anda third embodiment. A third embodiment will be described concretely bythe use of FIG. 9. FIG. 9 is a fragmentary sectional view of a displaydevice according to a third embodiment. FIG. 9 illustrates a partialsection of a display device according to a third embodimentcorresponding to the partial section illustrated in FIG. 5A.

In order to simplify a figure, a partial section is illustrated,excluding a cover 100 and a bonding member 110. A section of a left sideportion of a display device according to a third embodiment has the samebonding structure that a section of a right side portion of a displaydevice according to a third embodiment has.

With a backlight 140 b of a display device 10 d according to a thirdembodiment the frame 147 used in the display device 10 according to thefirst embodiment is removed. Furthermore, with the display device 10 dthe adhesive tape 130 used in the display device 10 according to thefirst embodiment is removed. In addition, an adhesive tape 350 is usedin place of the adhesive tape 150. The adhesive tape 350 is asingle-sided tape having adhesive force only on one face. In addition,an end face of a panel 120 protrudes out from an end face of thebacklight 140 b. As a result, there is a level difference between theend face of the panel 120 and the end face of the backlight 140 b.

As illustrated in FIG. 9, a long side 351 of the adhesive tape 350placed in the right side portion of the display device 10 d includes afirst bonding area 351 a and a second bonding area 351 b. The firstbonding area 351 a and the second bonding area 351 b are integrallyformed. Furthermore, with the display device 10 d the first bonding area351 a and the second bonding area 351 b are placed in regular positionsby bending the long side 351 at the border between the first bondingarea 351 a and the second bonding area 351 b. Positions where the firstbonding area 351 a and the second bonding area 351 b are placed will nowbe described concretely.

The first bonding area 351 a is placed on the rear surface side of areflector 148 and is bonded to a rear surface of the reflector 148.

The second bonding area 351 b includes a bonding portion 351 b 1 on thepanel side bonded to the end face of the panel 120, a bonding portion351 b 2 on the light guide side bonded to an end face of a light guide141, and a connection portion 351 b 3 which connects the bonding portion351 b 1 and the bonding portion 351 b 2. Furthermore, the connectionportion 351 b 3 is placed so as to fall from the bonding portion 351 b 1to the bonding portion 351 b 2. As a result, the connection portion 351b 3 covers the level difference between the end face of the panel 120and the end face of the backlight 140 b. Furthermore, the connectionportion 351 b 3 of the second bonding area 351 b is opposed to opticalsheets 144 to 146 of the backlight 140 b and a polarizer 124 with adetermined clearance (space) therebetween. In view of these respects, itis desirable to eliminate adhesive force from an inner face of theconnection portion 351 b 3 opposed to the optical sheets 144 to 146 andthe like. However, there may be cases where adhesive force is noteliminated from the inner face of the connection portion 351 b 3.

In addition, the second bonding area 351 b extends from end faces of apair of substrates 121 and 122. A portion of the second bonding area 351b is bent along the pair of substrates 121 and 122. Furthermore, an endface of the portion of the second bonding area 351 b is opposed to anend face of the polarizer 123. In this state, the portion of the secondbonding area 351 b bent along the pair of substrates 121 and 122 isbonded to a peripheral edge portion (portion not covered with apolarizer 123) of a front surface of the upper substrate 121.

The portion of the second bonding area 351 b bent along the pair ofsubstrates 121 and 122 is equal to or smaller than the polarizer 123 inthickness.

As has been described, with the display device 10 d the adhesive tape130 and the frame 147 used in the display device 10 according to thefirst embodiment are removed. Accordingly, when a display area is set,there is no need to meet the following restriction. A display area isset in planar view inside an area situated over the frame 147 or theadhesive tape 130. As a result, the distance from a peripheral edge of adisplay screen 120 a of the panel 120 to a display area 120 b isdecreased. Therefore, a display device having a narrow frame isrealized.

An upper side portion of the display device according to the thirdembodiment may also have the same structure as the right side portionillustrated in FIG. 9 has.

The third embodiment has been described. The same functions and effectsare also obtained for matters in the third embodiment which are the sameas those in each of the above embodiments.

Furthermore, of course it is understood that other functions and effectswhich are obtained by the situation described in the third embodimentand which are clear from the specification or which are conceivable bythose skilled in the art according to circumstances are realized by thepresent disclosure.

Fourth Embodiment

A fourth embodiment differs from the first embodiment in the dispositionof an adhesive tape (position where an adhesive tape is placed) and thepresence of a case of a backlight. Description will now be given withimportance attached especially to the differences between the firstembodiment and a fourth embodiment. A fourth embodiment will bedescribed concretely by the use of FIGS. 10A and 10B.

FIGS. 10A and 10B are fragmentary sectional views of a display deviceaccording to a fourth embodiment. FIG. 10A illustrates a partial sectionof a display device according to a fourth embodiment corresponding tothe partial section illustrated in FIG. 5A. FIG. 10B illustrates apartial section of a display device according to a fourth embodimentcorresponding to the partial section illustrated in FIG. 5B. In order tosimplify figures, partial sections are illustrated, excluding a cover100 and a bonding member 110.

A section of a left side portion of a display device according to afourth embodiment has the same bonding structure that a section of aright side portion of a display device according to a fourth embodimenthas.

With a display device 10 e according to a fourth embodiment a backlight140 c includes a case 149. The case 149 includes a bottom 149 b overwhich various optical members are placed and a sidewall 149 a erectedfrom a peripheral edge portion of the bottom 149 b in a positionsituated under a panel 120 in planar view. Furthermore, the adhesivetape 130 used in the display device 10 according to the first embodimentis removed. In addition, the frame 147 used in the display device 10 isremoved. Moreover, a frame 347 is newly placed opposite an end face of alight guide 141 and end faces of optical sheets 144 to 146.

With the display device 10 e the frame 347 is bonded to a reflector 148with an adhesive tape 160 placed between the frame 347 and the reflector148. Furthermore, the frame 347 has a stepped shape (also referred to asan L shape). That is to say, its lower portion protrudes out from itsupper portion to an inner periphery side in a cross-sectional view. Inaddition, a lower portion of the frame 347 is opposed to the end face ofthe light guide 141 and an upper portion of the frame 347 is opposed tothe end faces of the optical sheets 144 to 146. The optical sheets 144to 146 are placed so as to extend to a position where they are situatedover the lower portion of the frame 347 in planar view.

Moreover, with the display device 10 e an adhesive tape 450 is used inplace of the adhesive tape 150 used in the display device 10 accordingto the first embodiment.

The adhesive tape 450 is a double-sided tape having adhesive force onboth faces.

As illustrated in FIG. 10A, a long side 451 of the adhesive tape 450placed in the right side portion of the display device 10 e extendsthrough a space between the panel 120 and an end face of the sidewall149 a opposed to the panel 120 to the inside of the case 149. The longside 451 of the adhesive tape 450 includes a first bonding area 451 a, asecond bonding area 451 b, and a third bonding area 451 c. The firstbonding area 451 a, the second bonding area 451 b, and the third bondingarea 451 c are integrally formed. Furthermore, with the display device10 e each bonding area of the long side 451 is placed in a regularposition by bending the long side 451 at the borders between the bondingareas. A position where each bonding area is placed will now bedescribed concretely.

The first bonding area 451 a is placed in a position opposite an innerperipheral face (inner wall face) of the sidewall 149 a of the case 149and is bonded to the inner peripheral face.

Furthermore, the first bonding area 451 a is opposed to the end faces ofthe light guide 141 and the optical sheets 144 to 146 of the backlight140 c with a determined clearance (space) therebetween. In view of thisrespect, it is desirable to eliminate adhesive force from a face of thefirst bonding area 451 a opposed to each component of the backlight 140c. However, there may be cases where adhesive force is not eliminatedfrom the face of the first bonding area 451 a opposed to each componentof the backlight 140 c.

The second bonding area 451 b is placed between a polarizer 124 (panel120) and the end face of the sidewall 149 a opposed to the polarizer124, and bonds the panel 120 and the case 149 together. Accordingly, inorder to ensure a bonding area (bonding strength), the polarizer 124 isplaced in the right side portion of the display device 10 e so as toprotrude out on the outer periphery side of a polarizer 123.

The third bonding area 451 c is placed in a position opposite an endface of the panel 120 and one face of the third bonding area 451 c isbonded to the end face of the panel 120. Furthermore, a base material155 is bonded to the other face of the third bonding area 451 c in aposition corresponding to the end face of the panel 120.

In addition, the third bonding area 451 c extends from end faces of apair of substrates 121 and 122. A portion of the third bonding area 451c is bent along the pair of substrates 121 and 122. Furthermore, an endface of the portion of the third bonding area 451 c is opposed to an endface of the polarizer 123. In this state, the portion of the thirdbonding area 451 c bent along the pair of substrates 121 and 122 isbonded to a peripheral edge portion (portion not covered with thepolarizer 123) of a front surface of the upper substrate 121.

The portion of the third bonding area 451 c bent along the pair ofsubstrates 121 and 122 is equal to or smaller than the polarizer 123 inthickness.

As illustrated in FIG. 10B, on the other hand, a short side 452 of theadhesive tape 450 placed in the upper side portion of the display device10 e extends through a space between the panel 120 and an end face ofthe sidewall 149 a opposed to the panel 120 to the inside of the case149. The short side 452 includes a first bonding area 452 a and a secondbonding area 452 b. The first bonding area 452 a and the second bondingarea 452 b are integrally formed. Furthermore, with the display device10 e the first bonding area 452 a and the second bonding area 452 b areplaced in regular positions by bending the short side 452 at the borderbetween the first bonding area 452 a and the second bonding area 452 b.Positions where the first bonding area 452 a and the second bonding area452 b are placed will now be described concretely.

The first bonding area 452 a is placed between the polarizer 124 (panel120) and an end face of the sidewall 149 a opposed to the polarizer 124,between the polarizer 124 and an end face of the frame 347 opposed tothe polarizer 124, and between the polarizer 124 and the optical sheets144 to 146. Furthermore, the first bonding area 452 a bonds together thepolarizer 124 and the end faces of the sidewall 149 a and the frame 347opposed to the polarizer 124. Accordingly, in order to ensure a bondingarea (bonding strength), the polarizer 124 is placed in the upper sideportion of the display device 10 e so as to protrude out on the outerperiphery side of a polarizer 123.

The optical sheets 144 to 146 are opposed to the first bonding area 452a, but the optical sheets 144 to 146 are not bonded to the first bondingarea 452 a. That is to say, there is clearance (space) between theoptical sheets 144 to 146 and the first bonding area 452 a. The opticalsheets 144 to 146 are bonded to the panel 120, the light guide 141, andthe like in the lower side portion (on the light source side) of thedisplay device 10 e, but the optical sheets 144 to 146 are not bonded tothe panel 120, the light guide 141, or the like in the three remainingside portions (right side, left side, and upper side portions) of thedisplay device 10 e. As a result, the optical sheets 144 to 146accommodate thermal expansion or thermal contraction and the occurrenceof a display degradation phenomenon, such as moire, is prevented.

The second bonding area 452 b is placed in a position opposite an endface of the panel 120 and one face of the second bonding area 452 b isbonded to the end face of the panel 120. Furthermore, a base material155 is bonded to the other face of the second bonding area 452 b in aposition corresponding to the end face of the panel 120.

In addition, the second bonding area 452 b extends from end faces of thepair of substrates 121 and 122. A portion of the second bonding area 452b is bent along the pair of substrates 121 and 122. Furthermore, an endface of the portion of the second bonding area 452 b is opposed to anend face of the polarizer 123. In this state, the portion of the secondbonding area 452 b bent along the pair of substrates 121 and 122 isbonded to a peripheral edge portion (portion not covered with thepolarizer 123) of the front surface of the upper substrate 121.

The portion of the second bonding area 452 b bent along the pair ofsubstrates 121 and 122 is equal to or smaller than the polarizer 123 inthickness.

As has been described, with the display device 10 e, the frame 147 andthe adhesive tape 130 used in the display device 10 according to thefirst embodiment are removed and only the adhesive tape 450 is used forbonding (fixing) the panel 120 and the backlight 140 c together.

As a result, when a display area 120 b of the display device 10 e isset, there is no need to meet the following restriction. The displayarea 120 b is set in planar view inside an area situated over the frame147 or the adhesive tape 130. Accordingly, the distance from aperipheral edge of a display screen 120 a to the display area 120 b isdecreased. As a result, a display device having a narrow frame isrealized.

In addition, as illustrated in FIGS. 5A and 5B, with the display device10 according to the first embodiment the bonding area of the adhesivetape 130 is ensured in the width direction of the display device 10 (inthe horizontal direction of FIG. 5A) in order to bond (fix) the panel120 and the backlight 140 together with determined bonding strength. Onthe other hand, the bonding area of the adhesive tape 450 between thepanel 120 and the backlight 140 c is ensured in the thickness directionof the display device 10 e (in the vertical direction of FIG. 10A) inthe left or right side portion of the display device 10 e.

Because a bonding area is ensured in this way in the thickness directionof the display device 10 e, distance over which the adhesive tape 450extends in planar view is reduced in the left or right side portion ofthe display device 10 e. As a result, a frame area narrows and a displaydevice having a narrow frame is realized.

In addition, because the display device 10 e is housed in the case 149,the impact resistance of the backlight 140 c is improved.

The description has been given on the assumption that the upper sideportion of the display device 10 e according to the fourth embodimenthas the structure illustrated in FIG. 10B. However, the upper sideportion of the display device 10 e according to the fourth embodimentmay also have the same structure that is illustrated in FIG. 10A.Furthermore, the left or right side portion of the display device 10 eaccording to the fourth embodiment may have the same structure that isillustrated in FIG. 10B.

The fourth embodiment has been described. The same functions and effectsare also obtained for matters in the fourth embodiment which are thesame as those in each of the above embodiments.

Furthermore, of course it is understood that other functions and effectswhich are obtained by the situation described in the fourth embodimentand which are clear from the specification or which are conceivable bythose skilled in the art according to circumstances are realized by thepresent disclosure.

Fifth Embodiment

A fifth embodiment differs from the fourth embodiment in that anadhesive tape is bonded to an outer peripheral face (outer wall face) ofa case. Description will now be given with importance attachedespecially to the differences between the fourth embodiment and a fifthembodiment. A fifth embodiment will be described concretely by the useof FIG. 11.

FIG. 11 is a fragmentary sectional view of a display device according toa fifth embodiment. FIG. 11 illustrates a partial section of a displaydevice according to a fifth embodiment corresponding to the partialsection illustrated in FIG. 10A. In order to simplify a figure, apartial section is illustrated, excluding a cover 100 and a bondingmember 110.

A section of a left side portion of a display device according to afifth embodiment has the same bonding structure that a section of aright side portion of a display device according to a fifth embodimenthas.

With a display device 10 f according to a fifth embodiment an adhesivetape 550 is used in place of the adhesive tape 450 used in the displaydevice 10 e according to the fourth embodiment. The adhesive tape 550 isa single-sided tape having adhesive force only on one face.

As illustrated in FIG. 11, a long side 551 of the adhesive tape 550placed in the right side portion of the display device 10 f includes afirst bonding area 551 a.

The first bonding area 551 a is placed in a position opposite an endface of a panel 120 and an outer peripheral face of a sidewall 149 a ofa case 149 and is bonded to the end face of the panel 120 and the outerperipheral face of the sidewall 149 a.

Furthermore, the first bonding area 551 a extends from end faces of apair of substrates 121 and 122. A portion of the first bonding area 551a is bent along the pair of substrates 121 and 122. Furthermore, an endface of the portion of the first bonding area 551 a is opposed to an endface of the polarizer 123. In this state, the portion of the firstbonding area 551 a bent along the pair of substrates 121 and 122 isbonded to a peripheral edge portion (portion not covered with apolarizer 123) of a front surface of the upper substrate 121.

The portion of the first bonding area 551 a bent along the pair ofsubstrates 121 and 122 is equal to or smaller than the polarizer 123 inthickness.

The first bonding area 551 a may extend downward from the outerperipheral face of the sidewall 149 a and a portion of the first bondingarea 551 a extending from the outer peripheral face of the sidewall 149a may be bent along the case 149 to place it on a face of a bottom 149 bof the case 149 opposite to a face on which a backlight 140 c is placed.By doing so, a bonding area between the adhesive tape 550 and the case149 of the display device 10 f is increased. This makes it difficult topeel the adhesive tape 550 from the case 149. Even in this case, theadhesive tape 550 does not exert influence on display because theadhesive tape 550 is placed on the face of the bottom 149 b opposite tothe face on which the backlight 140 c is placed.

An upper side portion of the display device 10 f according to the fifthembodiment may also have the same structure that is illustrated in FIG.11.

The fifth embodiment has been described. The same functions and effectsare also obtained for matters in the fifth embodiment which are the sameas those in each of the above embodiments.

Furthermore, of course it is understood that other functions and effectswhich are obtained by the situation described in the fifth embodimentand which are clear from the specification or which are conceivable bythose skilled in the art according to circumstances are realized by thepresent disclosure.

The display devices described in the above embodiments may beincorporated in various electronic apparatus such as smartphones, tabletterminals, portable telephones, notebook-sized PCs, portable gamemachines, electronic dictionaries, television sets, and car navigationsystems.

All examples and conditional language provided herein are intended forthe pedagogical purposes of aiding the reader in understanding theinvention and the concepts contributed by the inventor to further theart, and are not to be construed as limitations to such specificallyrecited examples and conditions, nor does the organization of suchexamples in the specification relate to a showing of the superiority andinferiority of the invention. Although one or more embodiments of thepresent invention have been described in detail, it should be understoodthat various changes, substitutions, and alterations could be madehereto without departing from the spirit and scope of the invention.

What is claimed is:
 1. A display device comprising: a panel having afront surface and a polarizer disposed on the front surface; a backlightdisposed under the panel, the backlight including light sources, acircuit board for supplying drive signals to the light sources, a lightguide, a frame surrounding the light guide, and a reflector disposedopposite the light guide and the frame; and an adhesive tape having apair of first sides one of which is along the circuit board and a pairof second sides which connect end portions of the pair of first sides,and having a light blocking property, wherein: one of the second sidesof the adhesive tape is bonded to the front surface such that an endface of the adhesive tape is opposed to an end face of the polarizer, toan end face of the panel, to an outer end face of the frame, and to abottom face of the frame and the reflector therebetween; and one of thefirst sides of the adhesive tape is bonded to the bottom face of theframe and the reflector therebetween.
 2. The display device according toclaim 1, wherein: a width of the pair of second sides is greater than awidth of the pair of the first sides.
 3. The display device according toclaim 1, wherein: a width of the bottom face of the frame is greaterthan a width of the first sides adhered thereto.
 4. The display deviceaccording to claim 1, wherein: the second side of the adhesive tapecovers a level difference between the end face of the panel and theouter end face of the frame.
 5. The display device according to claim 4,wherein: the outer end face of the frame projects laterally with the endface of the panel, the adhesive tape includes a connection portionextending from the end face of the panel to the outer end face of theframe, and the connection portion is oblique corresponding the end faceof the panel.
 6. The display device according to claim 1, wherein: thebacklight further includes at least an optical sheet provided on thelight guide.
 7. The display device according to claim 6, wherein:another adhesive tape bonds the frame and the optical sheet to thepanel.
 8. The display device according to claim 6, wherein: an edge ofthe optical sheet is located on the frame.
 9. The display deviceaccording to claim 1, wherein: an end face of the first side of theadhesive tape flashes with an end face of the reflector.
 10. The displaydevice according to claim 1, wherein: both of the first sides of theadhesive tape bond the frame to the reflector.
 11. The display deviceaccording to claim 1, wherein: the one of the first sides of theadhesive tape only bonds the frame to the reflector.
 12. The displaydevice according to claim 1, wherein: both of the first sides of theadhesive tape only bond the frame to the reflector.
 13. The displaydevice according to claim 1, wherein: a length of the second side isgreater than a length of the first side.